In a yarn feeding device known from EP 0 567 045 A1, the holder is secured to a slide which is movable along the extension arm. The slide is coupled to an adjusting screw arranged in longitudinally positioned fashion in the extension arm, namely by means of a pin which is seated in the slide at the bottom and which can be lifted by means of an eccentric and a handle to decouple the slide from the adjusting screw. The slide can then be moved by hand on the extension arm into the gap position or removed from the extension arm. In the engaged state of the pin, the slide can also be moved gradually by means of the adjusting screw into the gap position. The gap position is needed to either replace the yarn braking body or the yarn braking element or to thread a new yarn, possibly by hand. The adjustment of the holder by means of the adjusting screw is time-consuming and troublesome. A manual adjustment requires considerable skill for coupling the pin and for adjusting the slide.
In a yarn feeding device known from EP 0 659 918 A1, the holder can be moved by remote control into the gap position by means of a compressed-air cylinder-piston unit. A new yarn is threaded pneumatically by blowing the yarn below the lifted yarn braking element therethrough. Since the piston is acted upon by a restoring spring, there is the risk in case of a manual threading operation or when the yarn braking element or yarn braking body is replaced that the holder will automatically return towards the braking position. Moreover, this is an expensive and troublesome solution which is not suited for a yarn feeding device with manual threading.